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- Network Working Group G. Malkin
- Request for Comments: 1387 Xylogics, Inc.
- January 1993
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- RIP Version 2 Protocol Analysis
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- Status of this Memo
-
- This memo provides information for the Internet community. It does
- not specify an Internet standard. Distribution of this memo is
- unlimited.
-
- Abstract
-
- As required by Routing Protocol Criteria (RFC 1264), this report
- documents the key features of the RIP-2 protocol and the current
- implementation experience.
-
- Acknowledgements
-
- The RIP-2 protocol owes much to those who participated in the RIP-2
- Working Group of the Internet Engineering Task Force (IETF). A
- special thanks goes to Fred Baker for his help on the MIB, and to
- Jeffrey Honig for the implementation experience.
-
- 1. Protocol Documents
-
- The RIP-2 protocol description is defined in RFC 1388 [1]. This memo
- suggests an update to the "Routing Information Protocol" (RFC 1058)
- [3]. The RIP-2 MIB description is defined in RFC 1389 [2].
-
- 2. Key Features
-
- While RIP-2 shares the same basic algorithms as RIP-1, it supports
- several new features. They are: routing domains, external route
- tags, subnet masks, next hop addresses, and authentication.
-
- 2.1 Routing Domains
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- Routing domains allow multiple RIP "clouds" to exist over the same
- physical network. This is a feature requested by several members of
- the working group. It allows simple policies to be constructed by
- grouping routers into domains which share routing information.
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- Malkin [Page 1]
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- RFC 1387 RIP-2 Analysis January 1993
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- 2.2 External Route Tags
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- The route tag field may be used to propagate information acquired
- from an EGP. The definition of the contents of this field are beyond
- the scope of this protocol. However, it may be used, for example, to
- propagate an EGP AS number.
-
- 2.3 Subnet Masks
-
- Inclusion of subnet masks was the original intent of opening the RIP
- protocol for improvement. Subnet mask information makes RIP more
- useful in a variety of environments and allows the use of variable
- subnet masks on the network. Subnet masks are also necessary for
- implementation of "classless" addressing, as the CIDR work proposes.
-
- 2.4 Next Hop Addresses
-
- Support for next hop addresses allows for optimization of routes in
- an environment which uses multiple routing protocols. For example,
- if RIP-2 were being run on a network along with another IGP, and one
- router ran both protocols, then that router could indicate to the
- other RIP-2 routers that a better next hop than itself exists for a
- given destination.
-
- 2.5 Authentication
-
- One significant improvement RIP-2 offers over RIP-1, is the addition
- of an authentication mechanism. Essentially, it is the same
- extensible mechanism provided by OSPF. Currently, only a plain-text
- password is defined for authentication. However, more sophisticated
- authentication schemes can easily be incorporated as they are
- defined.
-
- 2.6 Multicasting
-
- RIP-2 packets may be multicast instead of being broadcast. The use
- of an IP multicast address reduces the load on hosts which do not
- support routing protocols. It also allows RIP-2 routers to share
- information which RIP-1 routers cannot hear. This is useful since a
- RIP-1 router may misinterpret route information because it cannot
- apply the supplied subnet mask.
-
- 3. RIP-2 MIB
-
- The MIB for RIP-2 allows for monitoring and control of RIP's
- operation within the router. In addition to global and per-interface
- counters and controls, there is are per-peer counters which provide
- the status of RIP-2 "neighbors".
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- Malkin [Page 2]
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- RFC 1387 RIP-2 Analysis January 1993
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- 4. Implementations
-
- Currently, there is one nearly complete implementation of RIP-2. A
- "gated" implementation is now available with RIP-2, written by
- Jeffrey Honig at Cornell University. It may be acquired by anonymous
- FTP from gated.cornell.edu as pub/gated/gated-alpha.tar.Z. It
- implements multicasting, subnet masks, limited authentication, next-
- hop, and limited routing domain support. A RIP-2 version of ripquery
- is also available. The "gated" implementation does not yet support
- full subsumption rules, full authentication, full routing domains,
- and the MIB. It has been tested against itself and various RIP-1
- implementations.
-
- A second, complete implementation is under development by a vendor
- who's identity cannot be disclosed at this time.
-
- 5. References
-
- [1] Malkin, G., "RIP Version 2 - Carrying Additional Information",
- RFC 1388, Xylogics, Inc., January 1993.
-
- [2] Malkin, G., and F. Baker, "RIP Version 2 MIB Extension", RFC
- 1389, Xylogics, Inc., Advanced Computer Communications, January
- 1993.
-
- [3] Hedrick, C., "Routing Information Protocol", RFC 1058, Rutgers
- University, June 1988.
-
- 6. Security Considerations
-
- Security issues are discussed in section 2.5.
-
- 7. Author's Address
-
- Gary Scott Malkin
- Xylogics, Inc.
- 53 Third Avenue
- Burlington, MA 01803
-
- Phone: (617) 272-8140
- EMail: gmalkin@Xylogics.COM
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- Malkin [Page 3]
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